This is the same issue brought up every year at this time by those who actually pay an income tax. Since they currently are just slightly more than 50% of the income earners, they are barely in the majority but in any group there are always the do gooders who were sold the notion about the “progressive income tax” being beneficial.
IMO, the flat tax is not a bad idea, even an income tax with one rate is not. What should be done would be to eliminate the social security and medicare taxes and fund those from general revenues, something that is going to happen anyway as those systems are going bankrupt day by day now. Remove those in house “bonds” from the national debt too reducing the budget deficit a tad as the interest we pay on the intergovernment balances of these bonds is a shell transaction. Everyone pays is my motto.
Whenever I point out that the progressive income tax is the second plank of the Communist Manifesto people are surprised that we would have such a thing.